There are 16 possibilities in total: 5 that cause an increase, 5 that cause a decrease, and 6 that cause it to stay the same. With numbers this small, I tend to think you should just calculate them directly.

ways of getting a tie, then equal numbers for the others. Alternately, 1 way to have everything go to one side and 4 ways to get all but one; that's 5 for positive and 5 for negative, leaving 6 for ties.

Or you could do both calculations and breathe a sign of relief knowing that "math works".